Car radar devices are often used for recognizing a preceding vehicle or the like traveling, in which case, it is necessary to distinguish, from the preceding vehicle, objects, such as road signs and guideboards, which may not be obstacles due to their high positioning in the vertical direction relative to the road surface.
In order to overcome such problem, various methods, apparatuses, and the like are disclosed (for example, see Patent Literature 1). A radar device disclosed in Patent Literature 1 includes a receive antenna having an array antenna in which a plurality of element antennas are disposed in the left-right direction and a signal processor which electrically scans the antenna pattern of the receive antenna in the left-right direction to recognize objects present within a predetermined azimuth range in the left-right direction, based on a reception signal received by the receive antenna. In the radar device, at least some of the element antennas is disposed being shifted in the up-down direction from the others, and the signal processor uses a reception signal from the element antennas shifted in the up-down direction from the others to detect an object position in the up-down direction by the monopulse method.
According to the radar device disclosed in Patent Literature 1, by shifting in the up-down direction some of the plurality of element antennas, which are included in the receive antenna and disposed in the left-right direction, from the others, or providing the element antennas disposed in the up-down direction separately from the element antennas disposed in the left-right direction, the object position in the up-down direction can be detected within a desired angular range. That is, an amount of shift in the up-down direction or the disposition interval in the up-down direction can be set to be small as necessary. Therefore, a sufficient angular range for detection in the up-down direction can be provided.